mio's TTYPort is not exported #63
Description
It's not linked in the docs: https://docs.rs/tokio-serial/latest/tokio_serial/struct.SerialPortBuilder.html#method.open_native
While in Mio you can go to it's documentation: https://docs.rs/mio-serial/latest/mio_serial/struct.SerialPortBuilder.html#method.open_native